https://bugs.webkit.org/show_bug.cgi?id=90720

Patch by Benjamin Poulain <bpoulain@apple.com> on 2012-07-24
Reviewed by Geoffrey Garen.

In most String to CFString conversion, we should be able to use the "NoCopy" constructor and have
a relatively cheap conversion from WTF::String to CFString.

When the String is 8 bits, it was converted to 16 bits by getData16SlowCase() because of the call
to String::characters().

This patch adds a path for creating a CFString from a 8bits string using CFStringCreateWithBytes.

This is covered by existing tests.

* platform/text/cf/StringCF.cpp:
(WTF::String::createCFString): CFSTR() create static CFString, it is unecessary to retain it.
* platform/text/cf/StringImplCF.cpp:
(WTF::StringImpl::createCFString): The logic to avoid the StringWrapperCFAllocator has also been simplified.
The allocator creation is now closer to where it is useful.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@123504 268f45cc-cd09-0410-ab3c-d52691b4dbfc